PDA

View Full Version : Sun to Earth: No warming for next several decades - AAS predicts major drop in solar activity



c1ue
06-15-11, 09:21 AM
http://www.boulder.swri.edu/~deforest/SPD-sunspot-release/SPD_solar_cycle_release.txt (http://www.boulder.swri.edu/%7Edeforest/SPD-sunspot-release/SPD_solar_cycle_release.txt)



WHAT’S DOWN WITH THE SUN?
MAJOR DROP IN SOLAR ACTIVITY PREDICTED

A missing jet stream, fading spots, and slower activity near the poles say
that our Sun is heading for a rest period even as it is acting up for the
first time in years, according to scientists at the National Solar
Observatory (NSO) and the Air Force Research Laboratory (AFRL).

As the current sunspot cycle, Cycle 24, begins to ramp up toward maximum, independent studies of the solar interior, visible surface, and the corona indicate that the next 11-year solar sunspot cycle, Cycle 25, will be greatly reduced or may not happen at all.

The results were announced at the annual meeting of the Solar Physics
Division of the American Astronomical Society, which is being held this week
at New Mexico State University in Las Cruces:
http://astronomy.nmsu.edu/SPD2011/

“This is highly unusual and unexpected,” Dr. Frank Hill, associate director of the NSO’s Solar Synoptic Network, said of the results. “But the fact that three completely different views of the Sun point in the same direction is a powerful indicator that the sunspot cycle may be going into hibernation.”

Spot numbers and other solar activity rise and fall about every 11 years,
which is half of the Sun’s 22-year magnetic interval since the Sun’s
magnetic poles reverse with each cycle. An immediate question is whether
this slowdown presages a second Maunder Minimum, a 70-year period with
virtually no sunspots during 1645-1715.

Hill is the lead author on one of three papers on these results being
presented this week. Using data from the Global Oscillation Network Group
(GONG) of six observing stations around the world, the team translates
surface pulsations caused by sound reverberating through the Sun into models
of the internal structure. One of their discoveries is an east-west zonal
wind flow inside the Sun, called the torsional oscillation, which starts at
mid-latitudes and migrates towards the equator. The latitude of this wind
stream matches the new spot formation in each cycle, and successfully
predicted the late onset of the current Cycle 24.

“We expected to see the start of the zonal flow for Cycle 25 by now,” Hill
explained, “but we see no sign of it. This indicates that the start of Cycle
25 may be delayed to 2021 or 2022, or may not happen at all.”

In the second paper, Matt Penn and William Livingston see a long-term
weakening trend in the strength of sunspots, and predict that by Cycle 25
magnetic fields erupting on the Sun will be so weak that few if any sunspots
will be formed. Spots are formed when intense magnetic flux tubes erupt from
the interior and keep cooled gas from circulating back to the interior. For
typical sunspots this magnetism has a strength of 2,500 to 3,500 gauss
(Earth’s magnetic field is less than 1 gauss at the surface); the field must
reach at least 1,500 gauss to form a dark spot.

Using more than 13 years of sunspot data collected at the McMath-Pierce
Telescope at Kitt Peak in Arizona, Penn and Livingston observed that the
average field strength declined about 50 gauss per year during Cycle 23 and
now in Cycle 24. They also observed that spot temperatures have risen
exactly as expected for such changes in the magnetic field. If the trend
continues, the field strength will drop below the 1,500 gauss threshold and
spots will largely disappear as the magnetic field is no longer strong
enough to overcome convective forces on the solar surface.

Moving outward, Richard Altrock, manager of the Air Force’s coronal research
program at NSO’s Sunspot, NM, facilities has observed a slowing of the “rush
to the poles,” the rapid poleward march of magnetic activity observed in the
Sun’s faint corona. Altrock used four decades of observations with NSO’s
40-cm (16-inch) coronagraphic telescope at Sunspot.

“A key thing to understand is that those wonderful, delicate coronal
features are actually powerful, robust magnetic structures rooted in the
interior of the Sun,” Altrock explained. “Changes we see in the corona
reflect changes deep inside the Sun.”

Altrock used a photometer to map iron heated to 2 million degrees C (3.6
million F). Stripped of half of its electrons, it is easily concentrated by
magnetism rising from the Sun. In a well-known pattern, new solar activity
emerges first at about 70 degrees latitude at the start of a cycle, then
towards the equator as the cycle ages. At the same time, the new magnetic
fields push remnants of the older cycle as far as 85 degrees poleward.

“In cycles 21 through 23, solar maximum occurred when this rush appeared at
an average latitude of 76 degrees,” Altrock said. “Cycle 24 started out late
and slow and may not be strong enough to create a rush to the poles,
indicating we’ll see a very weak solar maximum in 2013, if at all. If the
rush to the poles fails to complete, this creates a tremendous dilemma for
the theorists, as it would mean that Cycle 23’s magnetic field will not
completely disappear from the polar regions (the rush to the poles
accomplishes this feat). No one knows what the Sun will do in that case.”

All three of these lines of research to point to the familiar sunspot cycle
shutting down for a while.

“If we are right,” Hill concluded, “this could be the last solar maximum
we’ll see for a few decades. That would affect everything from space
exploration to Earth’s climate.”

# # #

Media teleconference information: This release is the subject of a media
teleconference at the current meeting of the American Astronomical Society’s
Solar Physics Division (AAS/SPD). The telecon will be held at 11 a.m. MDT
(17:00 UTC) on Tuesday, 14 June. Bona fide journalists are invited to attend
the teleconference and should send an e-mail to the AAS/SPD press officer,
Craig DeForest, at deforest@boulder.swri.edu, with the subject heading “SPD:
SOLAR MEDIA TELECON”, before 16:00 UTC. You will receive dial-in information
before the telecon.

These results have been presented at the current meeting of the AAS/SPD.
Citations:

16.10: “Large-Scale Zonal Flows During the Solar Minimum -- Where Is Cycle
25?” by Frank Hill, R. Howe, R. Komm, J. Christensen-Dalsgaard, T.P. Larson,
J. Schou & M. J. Thompson.

17.21: “A Decade of Diminishing Sunspot Vigor” by W. C. Livingston, M. Penn
& L. Svalgard.

18.04: “Whither Goes Cycle 24? A View from the Fe XIV Corona” by R. C.
Altrock.

Andreuccio
06-15-11, 12:27 PM
Sun to Earth: I'll do what I can. After that, you're on your own - Temperature change associated with any reduction in sunspot activity would likely be "minimal"


http://news.yahoo.com/s/afp/20110614/ts_afp/usspacesun



"If we are right, this could be the last solar maximum we'll see for a few decades. That would affect everything from space exploration to Earth's climate," said Hill.

...

The temperature change associated with any reduction in sunspot activity would likely be minimal and may not be enough to offset the impact of greenhouse gases on global warming, according to scientists who have published recent papers on the topic.
"Recent solar 11-year cycles are associated empirically with changes in global surface temperature of 0.1 Celsius," said Judith Lean, a solar physicist with the US Naval Research Laboratory.


If the cycle were to stop or slow down, the small fluctuation in temperature would do the same, eliminating the slightly cooler effect of a solar minimum compared to the warmer solar maximum. The phenomenon was witnessed during the descending phase of the last solar cycle.


This "cancelled part of the greenhouse gas warming of the period 2000-2008, causing the net global surface temperature to remain approximately flat -- and leading to the big debate of why the Earth hadn't (been) warming in the past decade," Lean, who was not involved in the three studies presented, said in an email to AFP.


A study in the March 2010 issue of Geophysical Research Letters explored what effect an extended solar minimum might have, and found no more than a 0.3 Celsius dip by 2100 compared to normal solar fluctuations.


"A new Maunder-type solar activity minimum cannot offset the global warming caused by human greenhouse gas emissions," wrote authors Georg Feulner and Stefan Rahmstorf, noting that forecasts by the Intergovernmental Panel on Climate Change have found a range of 3.7 Celsius to 4.5 Celsius rise by this century's end compared to the latter half of the 20th century.

"Moreover, any offset of global warming due to a grand minimum of solar activity would be merely a temporary effect, since the distinct solar minima during the last millennium typically lasted for only several decades or a century at most."

c1ue
06-16-11, 11:50 AM
"Recent solar 11-year cycles are associated empirically with changes in global surface temperature of 0.1 Celsius," said Judith Lean, a solar physicist with the US Naval Research Laboratory.


If the cycle were to stop or slow down, the small fluctuation in temperature would do the same, eliminating the slightly cooler effect of a solar minimum compared to the warmer solar maximum. The phenomenon was witnessed during the descending phase of the last solar cycle.


This "cancelled part of the greenhouse gas warming of the period 2000-2008, causing the net global surface temperature to remain approximately flat -- and leading to the big debate of why the Earth hadn't (been) warming in the past decade," Lean, who was not involved in the three studies presented, said in an email to AFP.


A study in the March 2010 issue of Geophysical Research Letters explored what effect an extended solar minimum might have, and found no more than a 0.3 Celsius dip by 2100 compared to normal solar fluctuations.

Except for the little problem of CO2 'forcing' - supposedly CO2's secondary effects purport to change a straight 1 degree increase in temperature from a Little Ice Age recovery to a 4 to 6 degree increase.

You can't have it both ways: that the temperature will shoot up because CO2 multiplies solar irradiance effects on global temperatures going up, but not going down (or failing to go up).

Andreuccio
06-16-11, 05:00 PM
Except for the little problem of CO2 'forcing' - supposedly CO2's secondary effects purport to change a straight 1 degree increase in temperature from a Little Ice Age recovery to a 4 to 6 degree increase.

You can't have it both ways: that the temperature will shoot up because CO2 multiplies solar irradiance effects on global temperatures going up, but not going down (or failing to go up).

I don't know enough about the science to comment further.

As I read your posts on global warming, I keep hoping you're right; but I fear you're not. So I'm stuck between fear and hope. Which reminds me of a joke:

According to Freud, what comes between fear and sex?

c1ue
06-17-11, 11:24 AM
As I read your posts on global warming, I keep hoping you're right; but I fear you're not. So I'm stuck between fear and hope.

Of course knowing the science would be ideal - but the reality is that no one knows the science. It is a nascent field in which very little is well understood as can be seen by ongoing failures to be able to make predictions even a month into the future, much less the 100 years that is touted.

Given this, the other option is to examine the participants: their motivations, their integrity (or lack thereof), cui bono, etc etc.

AfricaGate (50% crop loss in Africa due to climate change related loss of rainfall by 2020 - graduate student paper, not peer approved)

AmazonGate(another claim of climate change related rainfall impact on the rain forest this time, from a web site)

GlacierGate(disappearing glaciers in the Himalayas by 2035 - actual projection 2305)

HurricaneGate (Hurricanes increasing due to climate change - Gore assertion beaten to death in numerous ways) along with its little brother TornadoGate (recent spate of US tornadoes/tornado deaths due to climate change)

REGate (80% of world's energy can be handled by wind/solar/biomass, Greenpeace employee touting own research using his role as IPCC lead author)

These indicate serious issues with motivation and integrity.

A glance at some of the funding behind AGW-CO2-Catastrophe also reveals that the participants either are making a living on promoting fear (Mann, Hansen, Trenberth) or have gained immensely from this movement (Gore).

Literally billions of dollars a year are being spent due to the fear you mention.

Note that I've never said there is no warming.

The issue here is what is causing the warming, how much warming will there really be, how much damage will result, and how best to address the overall situation.